The Best Laid Plans

Published: November 2015

Bulletin #49 November
2015

The Best Laid Plans

The title of this
month’s bulletin follows the spirit of a book by Sidney Sheldon and another by
Terry Fallis, each with the identical title “The Best Laid Plans”. In the same
vein, John Steinbeck wrote his novel “Of Mice and Men”. Each of these titles was
borrowed from a line in a poem by the famous Scots poet, Robert Burns, and paraphrased
from the original Scots as “the best laid plans of mice and men
often go awry” (Wiktionary). It is a proverbial expression used to
signify the futilityof making detailed plans when the ability to fully or
even partially execute them is uncertain (Wikipedia).

While the
outcome of orthodontic treatment in general is highly predictable, most of us
will agree that for the orthodontic treatment of cases with impacted teeth,
this is an appropriate and pertinent proverb. The multitude of factors that potentially
stand in the way of the successful execution of a plan to reduce the impaction
and bring about the alignment of the teeth are legion. Adverse factors may be
divided into those which are orthodontist-dependent, those which are
surgeon-dependent and those which are patient-dependent.1The patient-dependent factors may be further
sub-divided into those over which the patient has no control, which include
such features as abnormal tooth morphology, pathology of the impacted tooth,
gross ectopia, resorption of the root of an adjacent teeth and the patient’s
age.

Then
there are those factors where the patient does have control and where that control
needs to be exercised in an affirmative manner. Most of these come under the general heading
of compliance and include care of the appliances, maintaining a high level of
oral hygiene, cooperation with the placement of auxiliary aids, such as rubber
bands, headgears etc. and regular attendance for appliance adjustment.

The case report that is presented in
this bulletin is an example of failure to generate an adequate response to
compliance needs in the patient and how high hopes may be dashed because of a
lack of projection of the operator’s enthusiasm and confidence in achieving
success to an indifferent or apathetic patient.

Fig.
1.An oblique occlusal view of the
affected left side of the plaster casts of the patient, showing the deciduous
teeth (in red) and the permanent teeth (in yellow). The teeth are identified
according to the Federation
Dentaire Internationale (FDI) tooth numbering system. Note the erupting mesial
tip of the lateral incisorlingual to the deciduous first molar.

Case Report

Examination:

The patient was a 10.4 year old
female in the mixed dentition stage, with no specific complaint, but
considerable apprehension regarding the prospect of treatment. Her mother had
responded to the advice of an orthodontic colleague who had noted that the left
mandibular lateral incisor was erupting in an ectopic location, lingual to the
deciduous first molar on the same side (Fig. 1). A subsequent panoramic scan
was performed, followed by a cone beam CT series. The patient was then referred
to me for further advice and treatment.

At examination,the teeth were not clean even though the
mother and child asserted that she cleaned her teeth regularly. A thin and
diffuse layer of plaque was present on all the teeth and the gingival soft
tissues exhibited a mild degree of inflammation with redness and swelling. The
patient was given a hand mirror and these features were demonstrated to mother
and child. The dental hygienist then spent some time teaching them how and when
to perform her oral hygiene procedures and the patient was discharged and
reappointed a month later to check on her compliance – as would be recognizable
by improvement in the gingival picture.

Fig. 2. The initial panoramic
radiograph. Note the overall late developing dentition and the transposition of
MnI2C and maxillary MxCPm1 of the left side.

The malocclusion was diagnosed as
class 1 with slight bimaxillary dental retroclination, mild anterior crowding
and a deepened incisor overbite. In addition to the deciduous canines and
molars, the left maxillary and mandibular deciduous lateral incisors were
present and, from the radiographs, both had almost complete and unresorbed
roots (Fig. 2). The maxillary permanent lateral incisors were seen on the
radiographs to each have a palatal dens in dente, although only the right
incisor was erupted. The left deciduous first mandibular molar was almost
totally resorbed from within, apparently due to the acute angle of the
lingually-erupting lateral incisor.

Fig. 3. The graduated CBCT panoramic
view in the maxilla (Fig. 3a) with the red broken line indicating the location
of the cross-sectional slice (Fig. 3b).

Fig. 4. The graduated CBCT panoramic
view in the maxilla (Fig. 4a) with the red broken line indicating the location
of the cross-sectional slice (Fig. 4b).

The radiographs showed other
anomalies of the teeth on the left side of both jaws, namely a distinct
transposition of the unerupted left maxillary canine and first premolar4 (Fig.
3a, b) and of the mandibular canine and lateral incisor5 (Fig. 4a,
b). The child’s overall dental age was judged to be 7-8 years, i.e. 2-3 years
retarded in relation to her chronologic age, according to root development of
the permanent teeth.

Treatment plan:

A phase 1 orthodontic treatment was
proposed and commenced a month later,in
September 2014, with the following aims:-

1.Extraction
of the deciduous left mandibular lateral incisor, first molar and both canines.

2.Alignment
and minimal proclination of the
maxillary and mandibular incisors, including the grossly ectopic mandibular
left lateral incisor

3.Surgical
exposure of the ectopic permanent left canine

4.Appliance-driven
eruption and alignment of the ectopic mandibular canine

5.Extraction
of the maxillary deciduous canines, first molars and left deciduous lateral
incisor.

6.Monitoring
the future development of the left maxillary canine and premolar and phase 2
treatment at dental age 12 years (14-15 years chronologic age for the patient).

Treatmentprogress:

Because of her apprehension, simple removable “trainer” appliances2
were placed in September2014, largely
to help her overcome her initial fears and exaggerated gag reflex, and for her
to learn to tolerate foreign objects in her mouth. We recommend this in
particular for Special Needs patients who often suffer extreme forms of
apprehension and anxiety and in whom we have experienced a very high degree of
acceptance and subsequent improvement in management.3

In the first 3 months of treatment
in the present case, the patient damagedboth appliances, one of which had to be replaced!

In January 2015, the removable
appliances were discarded, due to continued damage and replaced with a mandibular
fixed lingual arch soldered to molar bands, with brackets placed on the
deciduous and erupted permanent teeth. In February and March, 5 posterior
brackets needed to be rebonded! In May 2015, all the brackets had been removed
by the patient and needed to be rebonded, but only after a long discussion with
mother and child. Following alignment and leveling in the mandible, a heavy
0.020mm stainless steel main arch was placed and the patient referred for the
mandibular extractions. At the same visit, maxillary fixed molar bands with
soldered transpalatal arch were placed and brackets bonded to all the uper
teeth. In June 2015, the solder joint on one side of the lingual arch became detached.

During these months, compliance in
oral hygiene was steadily dropping to an unacceptable level, despite efforts on
the part of the practice hygienist and my own admonishments, to the contrary. A
fairly widespread superficial decalcification was beginning to appear around
the brackets.

Fig. 5. Intraoral views of the
dentition after extraction of the deciduous canines and the left deciduous
lateral incisor and deciduous first molar and following anterior orthodontic
alignment.

Thus, in July 2015, when the lateral
incisors on the left side of both jaws had been brought into alignment, the
midlines adjustedand some space
gainedin the left mandibular canine/first
premolar area (Fig. 5), a new panoramic radiograph was taken, to consider the
future of orthodontic treatment.

The new panoramic film, taken 13
months after the initial one, showed much root development of the unerupted
premolars and canines and a minimal degree of improvement of the maxillary left
lateral incisor/canine transposition. Whereas the mandibular canine had
originally exhibited a strong mesial intrabony tip, the new film showed it to
be more horizontal and having migrated beyond the mandibular symphysis and
heading over to the left side of the jaw, deep down and palpable in the labial
depression of the labial side of the alveolar ridge, above the chin (Fig. 6a,
b).

Fig. 6a. The same panoramic view of
the dentition before treatment identifying the permanent (in yellow) and
deciduous (in red) teeth and defining the long axes of the transposed teeth.

Fig. 6b. At the prematurely aborted
phase 1 treatment, the panoramic view shows the considerable migration of the
unerupted left permanent canine (about 7-8mm) across the midline and a
worsening of its inclination. The teeth to be extracted, which include the
aberrant mandibular permanent canine, are marked x.

Given all the overt characteristics
of the child’s lack of compliance and the record of damage, it was decided to
abort the active orthodontic mechanotherapy and to extract the maxillary
deciduous canines and first molars, in the hope that the first premolars would
erupt rapidly and offer some space distal to the unerupted canines that would
encourage their eruption. The prospective efficacy of this procedure in solving
the incipient impaction of the transposed teeth on the left side is undoubtedly
questionable. However, given the several facets of the child’s lack of
cooperation, it was considered that
greater damage would be inflicted on her dentition by continuing treatment than
by leaving the situation in its present state of incompletion. In more
favorable circumstances, an attempt at rescuing the mandibular canine might
have been made, although its prognosis would been uncertain.5 There
can be little doubt that, with the passage of many more months, this tooth may
be expected to continue to migrate further distally on the right side.
Certainly, the big surprise in this case was to see the degree of movement over
the midline and its speed in just 13 months. Could this have been predicted?

Accordingly, the aberrant canine was
scheduled for extraction together with the above mentioned deciduous teeth and
simple removable retainers were prescribed for nocturnal wear only in September
2015, to hold the achieved alignment and gained space.

The patient will be followed up over
the next few years until a phase 2 procedure may be considered.In view of her tardy dental development,this is unlikely to be recommended much
before her 15th birthday, with much depending on the patient’s
future attitude to treatment.